I have just spent 3 days at a friend's house in Paris and the street markets were full of fresh mushrooms. I posted a Porcini mushroom soup here at the beggining of the week, which I find very nice for a wild mushroom version. But what about out of season. So it occured to me that as Button Mushrooms are the most cultivated species you can get them fairly easily and at a more comfortable price. So I decided to try a simple creamy mushroom soup, quite affordable and easy to make. I also made the soup in a french cuisine style, hence using butter instead of my usual Olive Oil cooking method and added a little Cognac. I tried the soup both hot and cold and liked it both ways. —Maria Teresa Jorge
Wash the mushrooms very well under running water. Then put them in a big bowl filled with water and add the lemon juice and leave for 1/2 an hour. Rewash them again, making sure they have no sand attatched. Remove any blemishes they might have. Keep them whole.
In a pot over medium heat, melt the butter, add the sliced onions and sweat. Add the Cognac and let the alcohol evaporate completely. Add the whole mushrooms, the milk and simmer over low heat for 30 minutes covered.
Remove 12 mushrooms, slice them and set aside. Add the cream and process the soup until very smooth and velvety. If too liquidy, return the pan to the heat and simmer 10 more minutes. If too thick add a little extra milk.
Add the laminated mushrooms. Season with salt and freshly ground WHITE pepper to your tasting. (It's important to use white pepper so you don't see specks of black in the white soup.
Serve hot or cold, sprinkled with finely chopped parsley. I also tried the soup with some freshly made white bread croutons but they were overpowering and the soup lost its "finesse" so I am sticking with the pure velouté.